diff --git a/src/scout_apm/core/config.py b/src/scout_apm/core/config.py
index 2e9fc99f..7e22b470 100644
--- a/src/scout_apm/core/config.py
+++ b/src/scout_apm/core/config.py
@@ -229,7 +229,7 @@ def __init__(self):
             "core_agent_log_level": "info",
             "core_agent_permissions": 700,
             "core_agent_socket_path": "tcp://127.0.0.1:6590",
-            "core_agent_version": "v1.5.0",  # can be an exact tag name, or 'latest'
+            "core_agent_version": "v1.5.1",  # can be an exact tag name, or 'latest'
             "disabled_instruments": [],
             "download_url": (
                 "https://s3-us-west-1.amazonaws.com/scout-public-downloads/"
diff --git a/tests/unit/core/samplers/test_cpu.py b/tests/unit/core/samplers/test_cpu.py
index 8e8e4cd3..4dc9e64d 100644
--- a/tests/unit/core/samplers/test_cpu.py
+++ b/tests/unit/core/samplers/test_cpu.py
@@ -3,7 +3,7 @@
 import datetime as dt
 import logging
 
-from psutil._common import pcputimes
+import psutil
 
 from scout_apm.core.samplers.cpu import Cpu
 from tests.compat import mock
@@ -27,9 +27,12 @@ def test_run_negative_time_elapsed(caplog):
 
 def test_run_negative_last_cpu_times(caplog):
     cpu = Cpu()
-    cpu.last_cpu_times = pcputimes(
-        user=1e12, system=1e12, children_user=0.0, children_system=0.0
+    # Create a mock cpu_times with very large values for user and system
+    # Use _replace() to maintain compatibility across different platforms
+    mock_cpu_times = psutil.Process().cpu_times()._replace(
+        user=1e12, system=1e12
     )
+    cpu.last_cpu_times = mock_cpu_times
 
     result = cpu.run()